A lot can happen in a decade. In 2007, the iPhone was introduced, Mad Men was the acclaimed new TV series, and the Dow Jones Industrial Average closed above 14,000 for the first time in history.

2007 also was the year that Watchfire Signs made its foray into digital billboards, and a good deal has changed in the outdoor display industry during the past 10 years.

Digital billboards are approved in nearly every state. Today 46 states have passed laws permitting digital billboards, compared to approximately 33 in 2007. As of July 1, 2016, the OAAA reports that there are approximately 6,700 digital billboards installed in the U.S., and there are now over 1,000 localities allowing digital billboards.

The Federal Highway Administration ruled digital billboards permissible in 2007. The ruling, which found that digital billboards didn't violate the Highway Beautification Act of 1968, allowed out of home companies to construct digital billboards along federal highways. Today, of the 46 states that allow billboards, only one prohibits digital billboards on "controlled highways."

Public/private partnerships are an acceptable means to build a digital signage network. In 2013, a ground-breaking agreement launched the first ever public-private partnership for a large-scale digital signage network in the United States. The City of Chicago contracted with Interstate JCDecaux to erect digital billboards at 34 locations along city-controlled expressways, with between 30 and 50 percent of advertising revenue generated going to the city.

The use of RSS feeds are making digital billboards even more dynamic. Dynamic feeds are gaining popularity on digital billboards as the lines are blurring between various digital platforms. Innovative advertisers today understand that they can capitalize on the unique capabilities of digital billboards to drive engagement in ways that static billboards cannot. Just about any kind of content can be added to digital billboards, including Twitter feeds, sports scores and news.

Digital billboards are more energy efficient. Digital billboards manufactured in the United States use about two-thirds less power than a decade ago. Higher efficacy LEDs require less energy, which results in lower operating costs.

Digital billboards have their own software to meet their unique needs.

The digital billboard industry has matured a great deal in the last decade. It's gratifying for us to look back at our very first digital billboards sold to DSW Signs in Cape Girardeau, Missouri, both of which are still operating and generating revenue today.

What changes have you seen in the digital billboard industry in the last decade?